The present invention refers to a tool for breaking, cutting or working of solid materials, said tool being intended to be rotatably mounted in a holder and being provided with a hard material cutting insert and a generally cylindrical shaft that is intended to be received in the holder, and that a clip is mounted on the shaft, the clip being generally cylindrical and having a slot that extends between the ends of the clip, and that the shaft has a tangentially extending groove.
In the tools of the type mentioned above two types of so-called clips are previously known.
The first type is usually called "dog-collar" and is, e.g., disclosed in U.S. Pat. No. 3,519,309. This type of clip has an axial extension that is only about half the length of the shaft, the whole of the clip being received in a groove on the shaft of the tool, the groove usually being located closer to the free end of the shaft than to the cutting end thereof. In mounted position the clip lies flush with the shaft on both sides of the groove. This means that an essential portion of the shaft has a direct contact with the recess in the holder that receives the tool. Such an arrangement causes a strong wearing both of the shaft and the holder upon rotation of the tool.
The other type of clip, called "long sleeve" extends along substantially the whole length of the shaft. At the free end of the shaft a collar is provided that constitutes a land surface for the clip and thus prevents axial displacement of the tool relative to the clip. When the tool is mounted in its holder the collar is flush to the clip. This means that there is a direct contact between the collar and the holder. This arrangement gives rise to a strong wearing of collar and holder already at a small inclination of the tool due to the cutting forces.
The aim of the present invention is to disclose a tool of the type mentioned above, the tool thus eliminating the shortcomings mentioned above by avoiding a direct contact between the shaft and the holder. Also a facilitated mounting of the tool is achieved.